import 'dart:convert';

import 'package:flutter/material.dart';

import 'package:kulinar_app/constants.dart';
import 'package:kulinar_app/widgets/error_widgets.dart';
import 'package:kulinar_app/widgets/toastbar_widget.dart';
import 'package:kulinar_app/widgets/custom_drawer_widget.dart';
import 'package:kulinar_app/models/data/shoplist_data_class.dart';

import 'package:flutter_gen/gen_l10n/app_localizations.dart';

class ShoplistView extends StatefulWidget {
  const ShoplistView({Key? key}) : super(key: key);

  @override
  ShoplistViewState createState() => ShoplistViewState();
}

class ShoplistViewState extends State<ShoplistView> {
  final FocusNode _focusNode = FocusNode();
  final TextEditingController _controller = TextEditingController();
  final GlobalKey<ScaffoldState> _scaffoldKey = GlobalKey<ScaffoldState>();
  final GlobalKey<AnimatedListState> _listKey = GlobalKey<AnimatedListState>();
  PersistentBottomSheetController? _bottomSheetController;
  bool _open = false;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      key: _scaffoldKey,
      appBar: AppBar(title: Text(AppLocalizations.of(context)!.category7)),
      drawer: const CustomDrawer(initialIndex: 4),
      floatingActionButton: _buildFloatingActionButton(),
      body: _buildAnimatedList(),
    );
  }

  Widget _buildFloatingActionButton() {
    return FloatingActionButton(
      child: Icon(_open ? Icons.remove_rounded : Icons.add_rounded, color: cIconColor),
      onPressed: () {
        if (_open) {
          _closeInput();
        } else {
          _bottomSheetController = _scaffoldKey.currentState!.showBottomSheet((context) => _buildBottomSheetInput());
          _open = !_open;

          setState(() {});
        }
      },
    );
  }

  // TODO: Sometimes exception "cant call insertItem of null" is thrown when first item is added or last is removed
  Widget _buildAnimatedList() {
    if (ShoplistData.shoplist.isEmpty) return const NoContentError();

    return AnimatedList(
      key: _listKey,
      initialItemCount: ShoplistData.shoplist.length,
      itemBuilder: (BuildContext context, int index, Animation<double> animation) {
        return SlideTransition(
          position: animation.drive(Tween(begin: const Offset(1.0, 0.0), end: const Offset(0.0, 0.0))),
          child: Dismissible(
            key: Key(_getUniqueKeyString(ShoplistData.shoplist[index])),
            background: _buildDimissibleBackground(true),
            secondaryBackground: _buildDimissibleBackground(false),
            child: ListTile(
              title: Text(ShoplistData.shoplist[index]),
            ),
            onDismissed: (_) {
              String _content = AppLocalizations.of(context)!.removed;
              String _actionLabel = AppLocalizations.of(context)!.undo;

              _removeItem(index);
              ToastBar.showToastBar(context, _content, actionLabel: _actionLabel, actionCallback: () => _addItem(ShoplistData.removed.removeLast()));
            },
          ),
        );
      },
    );
  }

  Widget _buildDimissibleBackground(bool left) {
    return Container(
      color: cPrimaryColor,
      /* 
      child: Row(
        mainAxisAlignment: left ? MainAxisAlignment.start : MainAxisAlignment.end,
        children: [
          Padding(
            padding: const EdgeInsets.all(8.0),
            child: Icon(
              Icons.delete_rounded,
              color: cIconColor,
            ),
          ),
        ],
      ),
      */
    );
  }

  Widget _buildBottomSheetInput() {
    _focusNode.requestFocus();

    return WillPopScope(
      child: Container(
        height: 75.0,
        color: cPrimaryColor,
        child: Padding(
          padding: const EdgeInsets.all(15.0),
          child: TextFormField(
            controller: _controller,
            style: cRecipeTitleStyle.copyWith(color: cIconColor),
            cursorColor: cIconColor,
            focusNode: _focusNode,
            textInputAction: TextInputAction.done,
            onEditingComplete: () {
              String _text = _controller.text.trim();

              _closeInput();
              _controller.clear();

              if (_text != "") _addItem(_text);
            },
          ),
        ),
      ),
      onWillPop: () async {
        return false;
      },
    );
  }

  String _getUniqueKeyString(String item) {
    return base64Encode(utf8.encode(item));
  }

  void _removeItem(int index) {
    _listKey.currentState!.removeItem(index, (_, __) => Container());
    ShoplistData.removed.add(ShoplistData.shoplist.removeAt(index));

    ShoplistData.save();

    setState(() {});
  }

  void _addItem(String string) {
    ShoplistData.shoplist.add(string);
    if (ShoplistData.shoplist.length > 1) _listKey.currentState!.insertItem(ShoplistData.shoplist.indexOf(string));

    ShoplistData.save();

    setState(() {});
  }

  void _closeInput() {
    _bottomSheetController!.close();
    _focusNode.unfocus();

    _open = !_open;

    setState(() {});
  }
}